chore(perf): Dedupe charge filter preload

[jdenquin]

Context

When computing customer usage, the plan's charges and their filter tree (charge_filters + charge_filter_values with their large properties jsonb) are
loaded from PostgreSQL twice per computation:

1. Invoices::CustomerUsageService#charges preloads them for the fee loop
2. Events::BillingPeriodFilterService#non_recurring_charges_with_events re-loads the exact same associations for the same plan

On large plans (~1,600 charge filters) each load costs seconds, and RefreshWalletsService pays this per subscription.

Description

Load the charge/filter set once and share it:

• Events::BillingPeriodFilterService accepts an optional charges: argument (pre-loaded charges with billable_metric and filters: {values: :billable_metric_filter}). When provided, non_recurring_charges_with_events, recurring_event_charges_and_filters and current_recurring_charges are
  resolved in memory instead of re-querying. Without it, behavior is unchanged, so CalculateFeesService and ProgressiveBillingService are unaffected.
• Invoices::CustomerUsageService passes its memoized charges relation to the service; since it is the same object, the fee loop then reuses the loaded
  records.
• find_each is replaced by each in the fee loop: find_each always re-queries in batches, which would have triggered the preload a second time.
• The usage preload now includes billable_metric: :filters, required by ChargeFilters::EventMatchingService to stay query-free on pre-loaded charges.

[jdenquin]

with #5882, we can again win around 50ms per subscription during a customer usage computation.
QA confirm it.